Regulation of tone in mechanical musical instruments.



PATENTED JAN. 21, 1908.

L. HUPPBLD.

MECHANICAL MUSICAL INSTRUMENTS.

REGULATION OF TONE IN APPLICATION FILED NOV. 1, 1906 Inventor.

Witnesses.

PATENT ()FETCE.

LUDWIG 'HUPFELD, OF LEIPZTU, GERMANY.

REGULATION OF TONE IN MECHANICAL MUSICAL INSTRUMENTS.

" subject 'of the King of Saxony, residing at Leipzig, Germany, have invented certain new and useful lmprove'ments in and Connected with the Regulation of tone in Mechanical Musical Instruments; and I do hereby declare the following to be-a full,

clear, and exact description of the invention.

This invention relates to the regulation of tone in mechanical musical instruments and more particularly to mechanical key instruments. v

Devices have already beenproposed for automatically controlling the stroke of the keys in mechanical key instruments, consisting of a regulating air bellows which controls a slide or other valve. The arrangement has been such that" a lever or the like, adjusted by hand or automatically by the note sheet, was soconnected with the air bellows, that the slide or other valve was not only afi'ected by the adjusting lever, but also at the same time by the air bellows. In this case, however, the reaction of the regulating air bellows on the adjusting arrange'-' merit could not be avoided, being particu= larly unpleasant when an automatic adjustment was efl'ected by the note sheet.

According to the present invention in con tradistinction to the known device, two slide valves are utilized, the one sliding over the other, one valve being adjusted by hand or the note sheet to suit the required strength of tone, while the other is connected with the regulating airbellows. The two valves working in cooperation simultaneously control the area of opening in the suction or pressure passage or trunkbut the valves are otherwise independent of each other.

The valve controlled by the regulating air bellows is preferably made to slide on the regulating slide valve but the reverse arrangement may be adopted. Both valves are arranged in. a be); of small compass. The adjustment which is very sensitive is quite independent of the weather or variations in the material due to change in temperature.

In the accompanying drawings, Figure 1 is a sectional elevation, and Fig. 2 a sectional plan of one form of valve according to the invention, Fig. 3 being a detail view, and Fig. 4 a sectional plan of another form.

In carrying out the invention according to 'one mode, for example in the application to a playing device worked on the suction princi Specification of Letters Patent.

Application filed November L 1906. Serial No. 341.615.

Patented Jan. 21, 1908.

ple, the opening, 0, forming communication between the wind chest, a, and the main suc- 'tion passage or trunk, b, is controlled by a slide valved, comprising a list slab having an orifice, 9, corresponding in size to the opening, 0. The valve d, may be moved so as to open or cut oil communication more or less according to the tone required, by any suitable rod f, and hand lever e, the so called expression lever.

By the use of the expression lover e to operate the valve d or ordinary manual tension throttle, the operator cannot follow the linetuation required by the varying demands of the pneumatics, as the playing of the composition progresses; Whereas by using the autopneumatic regulator 7L operating in conjunction with the primary or throttle (1, both controlling the same opening 0, whatever prescribed tension is set by the primary is automatically and uniformly maintained by the secondary or regulator valve h. The valve d according to the present invention is'tlwreforeprovided with an orifice corresponding insize with the opening 0 before referred to, and adapted to be brought more or less coincident therewith. A second slide valve, h, is movable over; the back of the first, the second valve being connected by a rod is, with and being moved by an air bellows i communicating through a suitable channel Z, with the wind chest (1.

Now if, for playing piano for example, the main opening 0, is partly closed by'adjusting the first valve d,'the orifice g, in the valve leading thereto is in turn more or less uncovi ed automatically by the second valve 71 according to the prevailing pressure in the wind chest at, which varies according to the number of notes simultaneously played, that is the number of perforations in the note sheet uncovered at any time. For instance, if one note is played only a small quantityof air enters the wind chest a, and the air in same is acted on strongly by the suction distend and move the secondary valve h, to

open the communicating passage 9, until the,

normal tension'in the wind chest a, is obtained. In this manner the secondary valve 7L, regulates the amount of'air passing through. .correspondingto the number of-note's played,

' automatically and independently of the position of the primary regulating valve d.

As the 'secondary valve h, slides 'on the back of the primary valve d, and has to, fit air tight thereon, it is pressed with considerable force against it and the bellows must overcome this'resistance. In order to avoid this diiiiculty the primary valvemay be formed with an open ended slot, 9, as shown in Fi s.'

3 and 4, the slot g, being open toward. t e wind chest the secondary valve it, only controlling the same, while there is asecond 0 enin or orificen in. the rimar valve (1;

for greater strength of tone.

If desired -other valves than slide valves.

may be used so long as the one acts'as the instrument, the combination. with the air trunk and the opening thereto; of a primary or throttle valve, a regulating bellows and a secondary valve, both of said valves controlling the opening.

2. In a mechanically played musical key instrument, the combination with the air trunk and the'opening thereto of a primary or throttle valve, a regulating bellows and a secondary valve operated thereby and sliding on the primary valveboth controlling the opening. r v

3. In a mechanically played lnuslcal key instrument, the combination with the air trunk and the opening thereto; of a primary,

or throttle valve controlling said opening and having an open-ended slot therein, a

regulating Howe and a secondary valve operatedithereby and sliding on and controlling the. primaryvalve and controlling tnr-'open-.-

ended slot.

' 4. In a mechanically played musical key instrument, the J combination with the air trunk and the opening thereto; ofa primary or throttle valve controlling said opening, 3 said'valve having anorifice and open-ended slot therein, a regulating bellows and a secondary valve operated thereby and controlling the open-ended slot.

5. In a mechanically played-musical key.

instrument, :the combination with the air trunk and the opening thereto; of a-primary or throttle valve controlling'said opening,

said valve having an orifice and an openended slot 9, a regulating-bellows and a secondary' valve operated thereby and sliding on the primary-valve to control said slot.

In testimonywhereof-I "have signed my name to this specification, in the presence of two subscribing witnesses.

UDWIG HUPFELD.

Witnesses: I

R DOLPH FnIcKE,

SoUTnARn P. WARNER. 

